package LC;

import java.util.Arrays;

/**
 * https://leetcode.com/problems/rotate-array/description/
 * Rotate an array of n elements to the right by k steps.
 * For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].
 * Note:
 * Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
 * [show hint]
 * Related problem: Reverse Words in a String II
 * Credits:
 * Special thanks to @Freezen for adding this problem and creating all test cases.
 */
public class LC_189_RotateArray_Recur {
    public static void main(String[] args) {
        int[] a = {1, 2, 3, 4, 5, 6};
        Solution.rotate(a, 3);
        System.out.println(Arrays.toString(a));
    }

    static class Solution {
        static void rotate(int[] nums, int k) {
            int temp = k % nums.length;
            reverse(nums, 0, nums.length - temp - 1);
            reverse(nums, nums.length - temp, nums.length - 1);
            reverse(nums, 0, nums.length - 1);
        }

        private static void reverse(int[] nums, int start, int end) {
            for (int i = start, j = end; i < j; i++, j--) {
                int temp = nums[i];
                nums[i] = nums[j];
                nums[j] = temp;
            }
        }
    }
}